Honda Insight Forum banner
1 - 2 of 2 Posts

· Registered
3 Posts
Discussion Starter · #1 ·
Thank you for your time.

I have the issue where the brake and battery light come on at weird times and also "flash" at times. All grounds are brand new in the car. It appears something is loose. By accident, I discovered I can fix the problem if I push on the window control panel and if I push hard enough, the problem goes away. My question is what is behind there that may be loose that I need to check?

I have a video demonstrating this but I am unable to do it per the site rules as I do not have enough posts. I was able to attach a picture of me pressing on the window control panel that when I push on it, the brake and battery light turn off.

Again, thank you for your time!


· Linsight Designer
4,931 Posts
That's an odd one...

1: The charging system malfunction light ("battery light") is only controlled by the DCDC converter in the back. Specifically, the DCDC has an open collector that pulls the line low, thus illuminating the battery light. This means that if the DCDC is disconnected, then the light cannot illuminate. Put another way, the instrument cluster has no failsafe that illuminates the battery light if the DCDC's battery light signal line is disconnected (or intermittently connected).

For comparison, the air bag ("SRS") light has such a failsafe, such that disconnecting the SRS computer will cause the SRS light to illuminate. Not so with the battery light... cut the line and the light will stay off.

2: If the battery light is on, then the brake light will also be on. This is because there is a diode in the instrument between these two lights... so the brake light can be on - with or without the battery light - but the battery light will always make the brake light come on, too.

I believe the IMA system is in a bad state, such that the DCDC is pulling the battery light line low, which should cause the battery light to illuminate. However, I suspect you might have a loose wire in the connector that plugs into the instrument cluster... my theory is that by pushing on the trim piece, you are also pushing on the instrument cluster, which is causing the DCDC's battery light line to disconnect (and thus turn off the light). This isn't a solid theory, but I can't think of anything else that would cause the light to turn off when you push on the dashboard.

To test this out, turn the key 'ON', but don't start the car. The battery light should always be on in this condition. If you can push on the dashboard and cause the battery light to turn off, then you need to find out where the wire has come loose.

The next test is to see if the DCDC is in fact disabled (i.e. illuminating the battery light)... you should get a voltage measuring device (e.g. DMM, cigarette lighter plug in, oscilloscope, etc)... something to read the voltage. If the measured voltage is above 13.5 V, then the DCDC is working. If the measured voltage is below 13 V, then the DCDC isn't working. We'll go from there.
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.